Annual incidence rates of 3157 cases of leptospiroses recorded within 1949 and 2004, caused by the main serovars ificant or borderly significant periodicities, resembling those known from solar and geomagnetic activity, were identified. By comparing them with the time course of Wolf numbers, an almost exact reciprocity of maxima and minima of Wolf numbers and leptospiroses was disclosed. It is hypothetized that the epizoonotic character of these diseases supports the putative dependence of its manifestation upon the nature including the sun. Surprisingly, no similar results were found, so far, in the world scientific registers.
Yearly numbers of new cases of this disease, collected over one half century,were processed by uncostomed biometrical tools – testing of randomness of the time sequence using Poisson and „contagious“ distributions, cosinor regression and crosscorrelation.The older experience of these authors – cycling of the daily numbers of cases during synodic lunar cycle – has been extended to the years´ scales: cycling contemporal with the Moon nutation period was found as significant. It is another evidence for a putative effect of gravity on bacterial virulence of Salmonella. In the mean time, experiments in NASA laboratories,USA found a dangerous increase of Salmonella virulence in microgravity conditions. Practical consequencies for the medical securing of space flight crews are indicated.